1. Field of the Invention
This invention relates to removal of burrs and similar unwanted projections from metals and other relatively hard materials.
2. Description of the Related Art
Removal of undesirable projections (collectively referred to as “burrs” herein) from a surface, such as a metal or other relatively hard material, is extremely important in the metal finishing industry. The presence of an unremoved burr on the surface of a part can cause numerous problems such as, for example, interference with the flow of a liquid or difficulty with the positioning of electrical charge-carrying lines.
Producers of vehicles, such as automotive vehicles, water-borne vehicles and aircraft are especially concerned with burr removal from the inner surfaces of tubes, cylinders and other containers and housings. However, in some cases, burr removal can be very difficult to achieve due to the location of the surface containing burrs (referred to herein as a “burred surface”). Furthermore, a burred surface will often have an irregular shape that makes burr removal very cumbersome and time consuming using existing burr removal tools. For example, when two intersecting apertures are drilled into a part, the breakthrough of the second aperture into the first aperture will produce a burred surface that is non-planar and is ellipsoid in shape. Due to the location and shape of this burred surface, the burrs located thereon cannot be easily abraded with a conventional burr removal tool.
Another significant problem is the unintentional scouring or gouging of a surface that may result during the advancement of a burr removal tool toward a burred surface. For example, when a burr removal tool is advanced through an aperture to remove a burr located within a part, the abrasive surface of the tool may inadvertently contact the wall of the aperture as the tool is advanced through the aperture, thereby removing material that is preferably left intact. Damage may also result when the rotating abrasive surface binds against a burr or other irregularity on the surface of the part and causes the tool to jump laterally or move in another uncontrollable manner.
Another difficulty with burr removal arises when it is necessary to use two or more different burr removal tools within a small space in a single container or housing. This commonly occurs when rough burr removal is to be followed by finishing, each requiring a different burr removal material or tool shape. Similarly, this difficult exists when a container includes two or more different materials, each with a burred surface that requires its own burr removal mechanism and associated material.